Computers are known to include a central processing unit, system memory, video graphics circuitry, audio processing circuitry, and peripheral ports. The peripheral ports allow the central processing unit to interface with peripheral devices such as a keyboard, a mouse, displays, external memory, etc. The audio processing circuitry receives digital audio signals from the central processing unit and produces analog signals that are provided to speakers. The video graphics processing circuitry receives graphics data from the central processing unit and processes it to produce pixel data. The pixel data, which is typically generated in a RGB format (red, green, blue), is subsequently displayed by a display such as a CRT monitor, LCD panel, etc.
The video graphics circuitry may further include video decoders and/or video encoders such that they may process video signals. Video signals are generally produced by video sources such as television broadcasts, VCRs, DVD players, camcorders, etc. As such, the computer is capable of displaying video signals on the display. Additionally, the computer may include a composite video output port and an S-video output port, which allow video signals to be sourced to a television.
In current implementations of video graphics circuitry, video input data, once processed, is treated similarly to graphics data. As is known, video data is converted to video graphics data via the video decoder and supplied to a graphics controller. The graphics controller manipulates the data and stores it in a frame buffer for a subsequent display on the computer monitor. If the video data is to be outputted to a television via the composite video output or the S-video output, the graphics controller retrieves the data from the frame buffer and provides it to a video encoder. As such, when computer received video signals are to be displayed on a television set, they are still processed by the graphics controller and stored in the frame buffer. Once stored in the frame buffer, the graphics controller retrieves the data and provides it to the video encoder. Thus, extra processing is done, which reduces the overall efficiency of a computing system and adds to the cost of such a system.
Therefore, a need exists for a method and apparatus for processing video signals to a plurality of video outputs with minimal extra processing.